<template>
  <div v-if="!item.hidden" class="el-sidebar_item">
    <template
      v-if="
        hasOneShowingChild(item.children, item) &&
        (!onlyOneChild.children || onlyOneChild.noShowingChildren) &&
        !item.alwaysShow
      "
    >
      <app-link v-if="onlyOneChild.meta" :to="resolvePath(onlyOneChild.path)">
        <el-menu-item :index="resolvePath(onlyOneChild.path)" :class="{ 'submenu-title-noDropdown': !isNest }">
          <item :icon="onlyOneChild.meta.icon || (item.meta && item.meta.icon)" :title="onlyOneChild.meta.title" />
        </el-menu-item>
      </app-link>
    </template>
    <el-submenu v-else ref="subMenu" :index="resolvePath(item.path)" popper-append-to-body>
      <template slot="title">
        <item v-if="item.meta" :icon="item.meta && item.meta.icon" :title="item.meta.title" />
      </template>
      <sidebar-item
        v-for="child in item.children"
        :key="child.path"
        :is-nest="true"
        :item="child"
        :base-path="resolvePath(child.path)"
        class="nest-menu"
      />
    </el-submenu>
  </div>
</template>

<script type="text/javascript">
import path from 'path';
import { isExternal } from '@/utils/validate';
import Item from './Item';
import AppLink from './Link';
import FixiOSBug from './FixiOSBug';

export default {
  name: 'SidebarItem',
  components: { Item, AppLink },
  mixins: [FixiOSBug],
  props: {
    // route object
    item: {
      type: Object,
      required: true
    },
    isNest: {
      type: Boolean,
      default: false
    },
    basePath: {
      type: String,
      default: ''
    }
  },
  data() {
    // To fix https://github.com/PanJiaChen/vue-admin-template/issues/237
    // TODO: refactor with render function
    this.onlyOneChild = null;
    return {};
  },
  methods: {
    hasOneShowingChild(children = [], parent) {
      const showingChildren = children.filter(item => {
        if (item.hidden) {
          return false;
        } else {
          // Temp set(will be used if only has one showing child)
          this.onlyOneChild = item;
          return true;
        }
      });

      // When there is only one child router, the child router is displayed by default
      if (showingChildren.length === 1) {
        return true;
      }

      // Show parent if there are no child router to display
      if (showingChildren.length === 0) {
        this.onlyOneChild = { ...parent, path: '', noShowingChildren: true };
        return true;
      }

      return false;
    },
    resolvePath(routePath) {
      if (isExternal(routePath)) {
        return routePath;
      }
      if (isExternal(this.basePath)) {
        return this.basePath;
      }
      return path.resolve(this.basePath, routePath);
    }
  }
};
</script>

<style lang="less" scoped>
.le-out {
  width: 676px;
  height: 172px;
  background: #FFFFFF;
  box-shadow: 0 0 20px 0 rgba(102, 102, 103, 0.1);
  border-radius: 8px;
  position: fixed;
  z-index: 100;
  left: 100px;
  top: 0;
}
</style>
